Terminating 16mm earth

[lineman]

http://t1.gstatic.com/images?q=tbn:ANd9GcQFjgwsxgkk_eVzmfoHhxNcLGcd2GBD8hpaHt5kWZWlwQGDe7Mi

From the original description i think that the op is referring to this type of service head sometimes seen with the terminal on the side

 

[batty]

Depends how old they are most I come across are sealed very occasionally some have the earth block on top but as you are not supposed to interfere with connections they are usually sealed.

 

[Zeespark]

The Earth connection on My TNCS head is an open one, when the head was changed the DNO installed a new head, energy meter, DP isolator, and 6181Y singles into the DP switch. No earth was provided for or terminated by the DNO, all left to the electrician at the time to do. This was in the last 4 years.

AndyGuinness